The fires began to produce haze, Muhammad Fandi, head of the North Kalimantan disaster mitigation office, confirmed here, Tuesday.
Fire-prone areas in the province include hinterland and border areas and those along the Trans-Kalimantan Highway toward Berau District, East Kalimantan, according to Fandi.
Haze shrouded Tanjung Selor, Bulungan, as fires reportedly occurred in the border area between Berau and Bulungan.
North Kalimantan Governor Irianto Lambrie has issued an instruction on banning land clearance using fire.
Forest and land fires are a recurrent phenomena in Indonesia, and the government has made all-out efforts to reduce their occurrence.
The mineral and peat fire in 2015 burnt 2.6 million hectares, mostly in the provinces of Riau, South Sumatra, Jambi, Central Kalimantan, West Kalimantan, and Papua, and cost US$16.1 billion as estimated by the World Bank in 2015, according to information on cifor.org.
Fires in Indonesia are caused by humans, both individually or collectively.
President Joko Widodo has committed to reducing fire during his term of office. Government actions have focused on fire suppression along with tackling biophysical and technological issues, such as through canal blocking and application of an early warning system.
Reporting by Iskandar Zulkarnaen, fardah